Many products such as industrial chemicals and compounds, food items, beverages, and medications should not be consumed or used after an expiration date (also often referred to as a “shelf life”). Typically, the expiration date for a product is printed on its container or other packaging. Unfortunately, many people fail to read expiration dates and therefore consume or otherwise use expired products. This can cause health problems, sometimes severe ones, especially when a food or medical product is consumed long after its expiration date. Similarly, use of expired industrial materials or chemical compounds such as adhesives, paints, reagents, etc. can lead to product failures.
Battery-powered shelf-life indicators have been developed to warn of expired products. These shelf-life indicators are typically embedded within or attached to product containers and count-down a time period corresponding to an expiration date. The indicators also display a time period remaining before the expiration date is reached and then provide an alarm or other visual or audible notice when the expiration date has been reached. Although such indicators are effective for products stored in visible or frequently visited places, they are less effective for alerting of expired products stored in warehouses, closets, pantries, cabinets, and other concealed or infrequently visited places because users may not see or hear the alarms before their batteries run-down. After the batteries of such an indicator die, a person may falsely assume the associated product is safe to consume or use because the indicator is no longer providing any indication of the lapsed expiration date.
Accordingly, there is a need for an improved way to alert consumers, industrial workers, and others of products with elapsed expiration dates.